Very fun game! I do think the font and typography choice is kind of unreadable especially during play. The post-processing and game design + upgrades make it very fun and satisfying to get more upgrades and kill things but after a certain point I just clicked the colored ones and I didn't have to put too much thought into it. I also do think you could experiment with making it more difficult like with more enemies(enemy types), difficulty modifiers, snowballing mechanics, etc.
Nice game!